Table 4.

Recommended Evaluations Following Initial Diagnosis in Individuals with RFC1 CANVAS / Spectrum Disorder

System/ConcernEvaluationComment
Neurologic Assessment by neurologist for gait & postural ataxiaNo validated clinical scale for RFC1 CANVAS / spectrum disorder exists; consider use of validated scales for eval of cerebellar disorder (e.g., SARA) & neuropathy (e.g., CMTNS). 1
Assess sensory neuropathy (sensory impairment, ↓/↑ reflexes, dysmetria) to evaluate for pain.Electrophysiologic studies (EMG & NCS) to establish presence of sensory neuropathy
Cerebellar dysfunction (dysmetria, dysdiadochokinesis, tremor, dysarthria, nystagmus, saccades & smooth pursuit)Brain MRI to assess presence/severity of cerebellar atrophy
Bilateral vestibular dysfunction (head impulse test & visually enhanced vestibular ocular reflex)Vestibular testing (video head impulse test, caloric response, vestibulo-ocular reflex gain tested using a rotatory chair) to assess vestibular hypofunction
Clinical assessment of symptoms of autonomic dysfunctionConsider autonomic testing in symptomatic persons.
PT/OT /
Rehabilitation 		Assess gross motor & fine motor skills & ambulation.
  • Prevention of falls
  • Adaptive devices (cane, walker, wheelchair)
  • PT
Speech For those w/dysarthria: speech/language eval
Feeding For those w/frequent choking or severe dysphagia, assess:
  • Nutritional status;
  • Aspiration risk.
Consider involving a gastroenterologist & nutritionist.
Respiratory For those w/disabling cough or respiratory symptoms: consider referring to pulmonary specialist.Consider:
  • Respiratory function testing, esp in non-ambulant individuals;
  • A sleep study if sleep apnea is suspected.
Genetic
counseling 		By genetics professionals 2To inform patients & their families re nature, MOI, & implications of RFC1 CANVAS / spectrum disorder in order to facilitate medical & personal decision making
Family support/
resources 		Assess:
  • Use of community or online resources;
  • Need for social work involvement for caregiver support.

CMTNS = Charcot-Marie-Tooth Neuropathy Score; EMG = electromyogram; MOI = mode of inheritance; NCS = nerve conduction study; OT = occupational therapy; PT = physical therapy; SARA = Scale for the Assessment and Rating of Ataxia

1.
2.

Medical geneticist, certified genetic counselor, certified advanced genetic nurse

From: RFC1 CANVAS / Spectrum Disorder

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